6io FLIGHT NOVEMBER 27TH, 1947
' Flight' Pilots a Jet
FUEL CONSUMPTION (CAL§)
Graphic indication of disnnce covered
and fuel used as the Vampire climbs to
10,003ft.
takes a step or two with pounds of lead holding him down.
The Vampire does not carry a simple magnetic com-
pass ; interference from the turbine would be excessive/
if it were mounted anywhere in the cockpit. The
(Remote Indica-
tor) compass DISTANCE COVER^Q (MIL?
master unit is o 20 40 6O
mounted as far '
from the engine
as possible, 3ft
from the tip in
the starboard
wing, and it did
its job well. I
caught the direc-
tional gyro spin-
ning on one or
two occasions,
but that was to
be expected.
As light was
failing I decided to dive home, and in spite of the violent
bumps, again thoroughly enjoyed the sensation of high
speed when I got nearer to the ground. The highest Mach
number reading was 0.69; the limit permitted is 0.75.
To get accustomed to the circuit height, and to reduce
speed, I made two circuits,
and then commenced an ap-
proach to land. Speed was
still about 280 m.p.h., so,
throttling back to 5,500
r.p.m., I extended the dive
brakes. The speed fell to
170 m.p.h. and, having com-
menced the down wind leg,
1 dropped the wheels and
selected 30 deg of flap. The
wheels locked down with a
resounding bump and air
passing over the nosewheel
produced a loud rumbling.
There is no warning horn for
the wheels, but an extra-bright red warning light is fitted
instead. The emergency switch operates the locks and
is only used with the hand pump or on an overshoot land-
ing to fold the wheels—an action not otherwise possible
if there is weight on them Other aircraft were on the cir-
cuit, so as a precaution I switched on lights.
It became necessary at this stage to use some more thrust,
the air speed having fallen to4 150 m.p.h. There was a
strong wind blowing, so I retracted the air brakes, which
1OO ZOO 3OO 4OO
M.P H. (IAS) soo
Variation of air mUe~, per
gallon with height and air
speed for the Vampire.
" No originality. That's the
troubl ."
were producing a certain amount of airirame vibration at
this speed, and commenced a wide turn-in at 140 m.p.h.
I selected full flap at 500 feet and found the speed dropped
slowly off with turbine r.p.m. of around 6,000. It was
necessary to hold the stick well forward to keep the nose
down and the speed at 130 m p.h. I started to level-out
at about 110 m.p.h.—a little on the fast side for the weight
—then closed the throttle and floated well down the runway
before touching-down in conventional tail-down attitude
and rocking forward on to the nosewheel.
Until the moment ot touch-down the Vampire remained
most responsive, and the elevators in particular were very
sensitive on hold-off. This I have confirmed on subse-
quent circuits, when I learned to like the approach, land-
ing and ground-handling characteristics of the Vampire
very well.
A feature of interest. is the relatively small change of
fore-and-aft trim experienced under all normal conditions
of flight. I did not fly the Vampire at maximum spee^'
maximum all-up weight or -at very high altitude, but,
Estimated thrust of
Goblii II at 10,200
r.p.m. in flight at
lO.OCOft. Although
gross thrust increases
with forward speed,
net thrust falls, re-
covers, then finally
exceeds the initial
value. This is due to
the deduction of in-
take dra8 from Sross
engine thrust.
except for the linal approach, when the nose must be held
down, and in a dive when there is also a slight tail-down
tendency, ^there is no need to move the elevator trimmer
irom the neutral position. Lowering of wheels, dive
brakes and up to 40 deg of flap cause no appreciable
change of trim. What changes there are tend to cancel
each other out on the approach. (Wheels down—nose up.
Flaps down—nose down.)
On return to the tarmac I had to think hard for a
moment how to stop the engine; no idle cut-outs, no
switches. All that one does, in fact, is to turn off the
high-pressure fuel cock and the Goblin cuts instantly.
Booster pump, master switch, compass, etc., are of course
switched off before leaving the aircraft.
In future I shall watch displays of low aerobatics and
high-speed flight by pilots of turbo-jet aircraft with more ~
understanding and even greater admiration. The
manoeuvres themselves are not particularly difficult to
execute ; the skill is chiefly in the timing and judgment of
position. Moreover, the physical strain imposed on even
experienced pilots should not be underestimated.
Piloting a jet aircraft has confirmed one opinion I had
formed: after flying as passenger in the Lancastrian jet
test beds, that few, if any, having flown in a jet-propelled
transport, will wish to revert to the noise, vibration ailc? *\
attendant fatigue of an airscrew-propelled piston-engined
aircraft.
24OO
2.3OO
' 2.200
2.100
2000
<H
IOO 2OO 3OO
M.P.H. 400 s"6o~~6bo
GONCORDIA PRODUCTION SUSPENDED
FOLLOWING the first stage of a programme of demonstra-tion flights on the Continent and in Africa and India, the
directors of Cunliffe-Owen Aircraft, Ltd., have decided that
production of the Concordia must he suspended. This regret-
table decision has resulted chiefly from the effect of the present
world situation. No more unfortunate circumstances could
have arisen for an export demonstration tour in view of the
existing unrest and the import and currency restrictions.
It had been estimated that orders for Go or 70 aircraft would
have to be obtained to make production of this twin-engined
feederline aircraft an economical proposition. Unfortunately
these were not forthcoming, largely because of lack of inter-
national purchasing facilities for this class of aircraft.
Work on the two large helicopters which are being built in
conjunction with the Cierva Autogiro Co., Ltd., will uot be
interrupted ; in fact it will probably be accelerated, and the
machines may be completed rather sooner than was expected.